x402-payable endpoint on Base returning a simple message for USDC micropayment.
What it does
Spark x420 is an x402-enabled HTTP endpoint hosted at x420.dev that returns a JSON message in exchange for a USDC micropayment on the Base network. The endpoint uses the x402 protocol (HTTP 402 payment-required flow): a client sends a GET request, receives a 402 challenge specifying the payment terms, and after providing an X-PAYMENT header with a valid USDC payment, receives a JSON response containing a message string.
The x420.dev platform is a "launchpad" for deploying x402-ready tokens with dedicated subdomains and APIs. Each deployed token gets instant liquidity on Clanker, with trading fees going to the deployer. The platform also describes a complementary "HTTP 420 Enhance Your Calm" protocol for graceful rate limiting and throttling, allowing agents to negotiate cooldown periods. The Spark endpoint specifically accepts payments up to 1 USDC (1,000,000 units in 6-decimal USDC) on Base, paid to address 0x93109d14F6665a9c9675290D3cD5A6c07bBAfdbd.
Documentation is extremely sparse — the /docs, /api, /pricing, and /README paths all return "Subdomain Not Found" errors. There is no OpenAPI spec, no detailed API documentation, and the output schema only specifies a single "message" field of type string. The actual content or utility of the returned message is unknown from available materials.
Capabilities
Use cases
- —Testing x402 payment protocol integrations
- —Demonstrating USDC micropayments on Base to AI agents
- —Prototyping pay-per-call API workflows
Fit
Best for
- —Developers experimenting with x402 protocol
- —Testing agent-to-API micropayment flows on Base
- —Learning how HTTP 402 payment challenges work
Not for
- —Production APIs requiring well-documented schemas and SLAs
- —Use cases needing complex data retrieval or computation
- —Applications requiring non-crypto payment methods
Quick start
curl -X GET https://x420.dev/api/spark \
-H "X-PAYMENT: <base-usdc-payment-token>"Example
Response
{
"message": "string"
}Endpoint
Quality
Minimal documentation exists — /docs, /api, /pricing, and /README all 404. The only concrete information comes from the x402 challenge header. No OpenAPI spec, no examples, no description of what the message contains. Effectively a stub listing.
Warnings
- —No API documentation available — /docs, /api, /pricing, /README all return 'Subdomain Not Found'
- —No OpenAPI or schema beyond the minimal outputSchema in the x402 challenge
- —Actual response content/utility of the 'message' field is unknown
- —Platform appears experimental; no SLA or uptime guarantees documented
Citations
- —The endpoint accepts USDC payments on Base network with maxAmountRequired of 1,000,000 (1 USDC)https://x420.dev/api/spark
- —x420.dev is a launchpad for deploying x402-ready tokens with dedicated subdomains and x402 APIshttps://x420.dev
- —Each token gets instant liquidity on Clanker, earning trading fees for the deployerhttps://x420.dev
- —The platform describes an HTTP 420 'Enhance Your Calm' protocol for rate limiting and throttlinghttps://x420.dev
- —/docs, /api, /pricing, /README paths all return 'Subdomain Not Found'https://x420.dev/docs